Derivatives - Derivative Liabilities and Collateral Pledged (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Derivative [Line Items]
Gross amounts of recognized liabilities	$ 98	$ 125
Derivative assets available for offset	0	0
Derivative liability	98	125
Derivative assets  available for offset	(43)	(21)
Collateral pledged	(21)	(82)
Net amount	34	22
Derivative liabilities not subject to master netting agreements	20	22
Derivatives, interest rate contracts
Derivative [Line Items]
Gross amounts of recognized liabilities	74	60
Derivative assets available for offset	0	0
Derivative liability	74	60
Derivative assets  available for offset	(29)	(7)
Collateral pledged	(12)	(31)
Net amount	33	22
Forward contracts
Derivative [Line Items]
Gross amounts of recognized liabilities	24	65
Derivative assets available for offset	0	0
Derivative liability	24	65
Derivative assets  available for offset	(14)	(14)
Collateral pledged	(9)	(51)
Net amount	$ 1	$ 0